Oil-switch.



E. M. HEWLETT.

OIL SWITCH.

APPLICATION IILED NOV. 14, 1904 1,023,310. Patented Apr. 16, 1912.

Fig.2

WltQesses lryvemon .A Horne) UNITED STATIILQPATENT OFFICE.

EDWARD M. HEWLETT, OF'SCHENECTADY, NEW YORK, ASSIGNOR TOcGENERAL ELEC- TRIC COMPANY, A CORPORATION OF NEW YORK.

OIL-SWITCH.

,Specificationof Letters latent.

Patented Apr. 16, 1912.

T all whom it may concern:

Be it known that I,- EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Oil-Switches, of

- switches of the oil break type such as used which the following is a specification.

The present invention relates to electr1c in installations handling currents of high potential and large amperage, and has particular reference tothe construction of the oil pot or inclosure in which the arc is drawn.

The principal object of the invention is to improve the effectiveness of this type of switch by providing a novel oil pot construction by which the pressure created by the arc is utilized in extinguishing the arc.

In carrying out my invention I provide the oil pot with means for confining the ressure created by the are within the neigh orhood of the arc and subsequently directing it against the are so as to extinguish it. It is obvious that oil pots of various forms may be employed to accomplish this result, and I have disclosed jointly with Charles E.

Eveleth another form in an application No. a

. drawn at one side of this partition uts the oil under pressure in that portion o the pot and forces it through the o ening in the battle-plate. At the instant 0 separation of the contacts the action of the are on the oil begins and the flow of oil through the opening in the bathe-plate continues until the pressure subsides after the arc is ruptured.

ince the point of initial separation of the contacts is some distance from the opening I I in the battle-plate, and since it is at this point of se aration that the pressure is applied to the 011, it follows that there will be a current of oil from the neighborhood of the arc along the movable contact and out through the opening.-- This current is instrumental in carrying away the conducting gases and vapors from their effective position between the contacts and thereby in increasing theresistance of the arc path. In addition to being subjected to this current of oil, the arc is also subjected to pressure. This is brought,

about by making the clearance between the movable contact and the wall of the opening in the baffle-plate such that the oil cannot escape rapidly enough to keep down the pressure in the neighborhood of the are. This pressure forces the oil to close in upon the arc, or rather prevents the latter from materially increasing in cross-section. At the same time the oil rapidly absorbs the heat of the arc and assists in chilling the vapor. In case the arc persists until the terminal of the movable contact passes through the opening in the bafile-plate, the plate will act to mechanically. restrict the cross-section of the arc and thereby assist in extinguishing it. Thus it will be seen that the arc is subjected first to the mechanical action of the current of the oil along the movable contact and, if this is insufficient to extinguish it, then to the mechanical action of the bathe-plate together with thestrong current of oil through the opening. This construction has been found very effective in extinguishing the arc. a I

A further understanding of the invention will be best obtained upon reference to the following. detailed description taken in connection with the accompanying, drawing which illustrates the preferred construction.

The various features and aspects of the.

invention will be particularly set forth in the appended claims.

of an oil switch having an oil-pot constructed in accordance with the present invent-ion; and Fig. 2 is a sectional elevation of the. oil potdrawn to an. enlarged scale.

Referring in detail to said drawing, 10 designates the oil pot which is here shown as a closed cylinder provided with a yielding contact 11 at its lower end and an insulating guide 12 at its upper end throu h which the contact rod 13 is adapted to e moved into and out of engagement with the contact 11. The oil-pot is provided with a suitable cover 13 and interior insulating lining 14. In the present instance a plurality of oil pots is employed for each circuit. These oil-pots are arranged in pairs located within fire-proof cells formed by the brick walls 19 and the fire-proof doors 20. Each pot is mounted directly upon a ter- 7 Figure 1 of said drawing is an elevation 4 which extends upward through the cap 21 of the cell structure. When the switch is in the closed position circuit is completed between the terminals 17 by way of the contacts 11 and 13 and the yoke 24. The con-- struction thus far described constitutes no part of the present invention but is one Evhich has been largely employed heretoore.

It will be apparent that in a switch construction such as the above, when the arc is drawn between the contacts, considerable gas is evolved at the lower end of the pot and this, when rupturing a large amount of energy, has the eifect of throwing the oil upward very much like a piston, and sometimes with suiiicient force to spill the oil from the pot, thus forcing the oil away from the are where it should be retained in order to extinguish it. By the present invention, this pressure is utilized for this purpose. In pursuance of this object I divide the oil pot 10 into two compartments by .means of a battle-plate or partition 15, which is located near the lower end of the pot in a position to pocket a certain portion of the oil in the neighborhood of the lower contact. The battle-plate 15 is provided with a central opening through which the contactrod'13 moves. This opening is somewhat larger in diameter than the contact 13 so that there is a clearance through whichformation of the arc, and as the contacts.

separate it will tend to carry the conducting vapors and gases produced by the are upward along the contact 13 and out intothe upper compartment. At the same time the pressure exerted upon the oil will react to compress the arc stream. 'Ifthe arc is not broken by the combined action of 'thecurrent of oil and the' pressure in the lower compartment b'ut persists it will be drawn through the opening 16 into the upper compartment. In passing through the opening the arc will be mechanically contracted by the bathe-plate l5 and will be torn apart by the current of oil flowin upward through the opening. here oil is omitted, the air within the pot will be subjected to similar action.

The rupturing of circuits carrying large amounts of energy produces an enormous pressure in the lower. compartment of the oil-pot. This pressure is counteracted by the oil-pot structure which must be sufliciently strong to withstand it. It is obvious that this strain on the pot may be relieved and the capacity of the switch thereby increased either by increasing the size of the opening 16- or by decreasing the amount of oil in the pot sufiiciently to bring its level below the battle-plate and leave an air cushion between its surface and the baffle-plate. It will be apparent to those skilled in the art that the position of the bafile-plate may also be varied to suit certain conditions of service.

In the operation of switches of this type some poweractuated mechanism is usually employed. For the purpose therefore of illustrating a completely operative device, I have shown in the present instance pneumatic means for reciprocating the movable contacts of the switch. The means illustrated is substantially the same as that disclosed'in my prior application, Serial Number 4314, fi'led February 17, 1900. It is of course obvious that other motor mechanisms might be employed equally as well and in fact the pneumatic mechanism described and shown herein hasbeen practically superseded in practice by electric actuating mechanism but I have desired to illustrate pneumatic means because of its simplicity. This pneumatic mechanism is mounted on the cap 21 of the cell structure of the switch and com- .compressed air or other fluid through the supply pipes 25, 26 and 27 to either side of the piston. The supply of fluid to the c linder is controlled by a valve 28 provided with suitable supply and exhaust ports. It

.is obvious that the piping may be arranged in any desired manner and that the controlling valve 28 may be located at a point some distance from the main switch in order to insure safety to the operator. From the above it will be apparent that when air is admitted through the pipes 25 and 27 to the under side of the piston it 'will be forced upward and at the same time the contacts 11 and 13 in each of the oil-pots will be separated and the circuit broken in the manner previously described. On the other hand, if air is admitted through the pipe 26 to the upper side of the piston, it will be forced downward and the circuit thereby closed. In order to retain the switch in its open position, that is with its iston up, without maintaining air pressure in the lower end of the cylinder, I provide a latch 29 which engages a-collar 30' at the upper end of the wooden rod 2 F. This latch is normally drawn into engagement with the collar by gravity.- In order to release the latch, a releasing pin 30 is provided. This pin at its lower end engages the latch 29 and at its upper end is secured to a diaphragm located in a chamber 31 and in communication at its upper side through the pipin upper end of the cylinder. ith this organization, when airis admitted to the upper end of the cylinder it will also be admitted to the upper side of the diaphragm and will force the pin 30 downward against the latch 29 thereby releasing it and allowing the air on the upper side of the piston to forcibly close the switch.

It will be obvious to those skilled in the art that many alterations and modifications may be made in the specific construction herein disclosed without departing from the spirit and scope of my invention. I thereterms of the ap fore do not wish to be limited to the specific matter disclosed but aim to cover by the nded claims all such alterations and modifications.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric switch comprising separable contacts, a closed chamber therefor contain ing insulating fluid, and immovable means located therein for confining the insulating fluid when put under pressure by the arc and directing the insulating fiuid against the are so as to extinguish .it.

2. An electric switch comprising a closed chamber, separable contacts arranged to break therein, and an immovable partition therein located above the break point and provided with an opening for the passage of the movable contact.

3. An electric switch comprising separable contacts arranged to break under oil, a closed chamber for the oil, and immovable means located therein for confining the oil when put under pressure by the arc and directing it against the arc so as to extinguish it.

4. An electric switch comprising separable contacts arranged to break under oil, a closed chamber for the oil,and an immovable apertured partition therein through which one of said contacts passes in drawing the arc.

5. An electric switch comprising a closed chamber containing oil, separable contacts arranged to break therein, and communicating means between different portions of said. chamber arranged to cause the pressure produced by the arc to direct oil against the arc so as to extinguish it.

32 with the 6. An electric switch comprising an oil pot, separable contacts arranged to break therein under oil, and communicating means between diiferent portions of said pot arranged to conduct the oil displaced-by the are against the are so as to extinguish it.

7. An electric switch comprising a two compartment chamber containing oil, separable contacts arranged to break in one of said compartments, and communicating means therebetween arranged to direct oil put under pressure produced by the are against the are so as to extinguish it.

8. An electric switch comprising a two compartment oil pot, separable contacts arranged to break in one of said compartments under 011, and communicating means therebetween arranged to conduct the oil displacedby the arc gases against the arc so as to extinguish it.

9. An electric switch comprising a two compartment oil pot, separable contacts arranged to break in one of said compartments, and an oil conducting passage therebetween arranged to conduct the oil displaced by the arc gases against the arc so as to extinguish it.

10'. An electric switch comprising a two compartment oil pot, one of which compartments is filled withoil, separable contacts arranged to break in the filled compartment,

and communicating means between the com partments for directing the oil put under pressure by the arc gases against the are so as to extinguish it. c

11. An electric switch comprising a two compartment oil pot, one of which compartments is filled with oil, separable contacts arranged to break in the filled compartment,

and the oil conducting passage between said compartments arranged to conduct the oil displaced by the arc gases against the are so as to extinguish it.

- 12. An electric switch comprising a two compartment oil pot, a communicating passage therebetween, and separable contacts arranged to break under oil in one compart ment and to draw the are through the com municating passage into the other compartment, whereby the oil put under pressurein one compartment prior to the other escapes through the communicating passage thereby compressing and extinguishing the are.

13. An electric switch comprising a two compartment oil pot one of which compartments is filled with oil, a communicating passage therebetween, and separable contacts arranged to break in the filled compartment and draw the are through the communicating passage to the other compartment whereby the oil put under pressure in one compartment prior to theother, escapes through the communicating passage thereby compressing and extinguishing the'arc.

14. An electric switch comprising an oil chamber, separable contacts arranged to break therein under oil, one of said contacts movable into and out of the oil, and means in the path of movement whereby the oil put under pressure by the arc is utilized in extinguishing the arc.

15. An electric switch comprising an oil compartment, separable contacts arranged to break therein under oil, and an escape opening permanently open to the 'oil displaced by the arc gases arranged so as to direct the escaping oil against the arc and to conduct the oil to said compartment after the arc is extinguished,

16. An electric switch comprising an oil pot partially filled with oil, a contact at the lower end of the pot, a cooperating movable contact extending into the pot through its upper end, and an immovable partition therein located below the oil level and provided with an opening for the passage of the movable contact.

17. An electric switch comprising an'oil pot, separable contacts therein arranged to break under oil, a partition in said pot located adjacent to the break point and extending transversely of the path of contact movement, and an escape opening thereinfor the passage of the oil put under pressure.

18. In an oil switch, an oil pot having a transverse fiat partition extending from wall to wall, and dividing theinterior of the pot into two compartments, said partition In witness whereof I have hereunto set "my hand this 12th day of November, 1904.

ED'WARD M. HEWLETT. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

